Device interlocking with a compartment

ABSTRACT

A fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore, a first opening at a first end of the interior bore, and a shoulder that divides the interior bore into a plunger bore and an outer bore. A plurality of overhangs is formed as part of the housing and extends into the outer bore, a plunger is positioned within the space and is operable to reciprocate along an axis within the plunger bore, and a valve cover is coupled to the housing and positioned to engage the shoulder to close the first opening. A valve cover retainer is positioned within the outer bore and includes a plurality of projections arranged to selectively engage the plurality of overhangs to sandwich the valve cover retainer between the valve cover and the housing to lock the valve cover into engagement with the shoulder.

RELATED APPLICATION DATA

This application claims priority to U.S. Provisional Application No. 62/118,366 filed Feb. 19, 2015, the contents of which are fully incorporated herein by reference.

BACKGROUND

The present invention concerns a device adapted for interlocking engagement with a compartment in a fluid end housing of a pump and an anti-rotation cap.

High pressure reciprocating pumps, such as the pump described in US publication 2014/0086774 have fluid ends. The fluid ends have a housing. The housing has a discharge bore, a suction bore, a further bore, and a cross bore intersection. The further bore is associated with a pumping member such as a piston or plunger. The further bore shown in US publication 2014/0086774 is associated with a plunger. The discharge bore, the suction bore, and the further bore each open into the cross-bore intersection. A suction valve assembly is in the suction bore and a discharge valve assembly is in the discharge bore. In a well-known manner, during the upstroke of the pumping member, fluid is taken into the housing over the suction valve and into the suction bore and cross-bore intersection. During the pumping member's downs stroke, the fluid taken in is discharged through the discharge bore and over the discharge valve assembly and out the fluid end housing.

The fluid end housing also has a valve access bore or conduit. The valve access conduit/bore allows for the removal and installation of the discharge and suction valve assemblies from the housing. During operation, the valve access conduit is sealed off with a valve cover. The cover is held in place by a retainer. The retainer is threadably engaged to the housing.

SUMMARY

A portion of a housing delimits a compartment. The compartment has a plurality of projection compartments with void spaces and a plurality of lock compartments with void spaces. The lock compartment void spaces and projection compartment void spaces are arranged in a circumferential direction in an alternating pattern with one another. Preferably every lock compartment is between, in the circumferential direction, a pair of projection compartments and every projection compartment is between, in the circumferential direction, a pair of lock compartments. Preferably the projection compartment between the pair of lock compartments is the only projection compartment in a space delimited in the circumferential direction by the pair of lock compartments, and the lock compartment between the pair of projection compartments is the only lock compartment in a space between the pair of projection compartments.

A device has a plurality of projections which extend radially outward relative to a central device axis. The device is selectively moveable while in the compartment from an unlocked orientation to a locked orientation and vice versa by relative rotational movement of less than 480 degrees. In the unlocked orientation each projection is in a different one of the projection compartments. In the locked orientation, each retainer projection is in a different one of the lock compartments. In the locked orientation the compartment and device are interlocked.

Each projection of the device has a surface axially spaced, in a first direction along the central device axis, from a second end of the device. The surface is inclined and helical. The incline, going in a second circumferential direction (counterclockwise) around the device central axis, extends away from the second end of the device in the first axial direction along the device central axis. The incline is helical. The helical form of the incline has a pitch. Each projection also has a surface which is oppositely facing from said inclined surface. In one embodiment of the device the inclined surface is inclined relative to the oppositely facing surface. In one embodiment the projection increases in thickness along the helical incline.

In one construction, a fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore, a first opening at a first end of the interior bore, and a shoulder that divides the interior bore into a plunger bore and an outer bore. A plurality of overhangs is formed as part of the housing and extends into the outer bore, a plunger is positioned within the space and is operable to reciprocate along an axis within the plunger bore, and a valve cover is coupled to the housing and positioned to engage the shoulder to close the first opening. A valve cover retainer is positioned within the outer bore and includes a plurality of projections arranged to selectively engage the plurality of overhangs to sandwich the valve cover retainer between the valve cover and the housing to lock the valve cover into engagement with the shoulder.

In another construction, a fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore and a shoulder that divides the interior bore into a plunger bore and an outer bore, a plunger positioned within the plunger bore and operable to reciprocate along an axis within the plunger bore, and a plurality of overhangs formed as part of the housing and extending into the outer bore, the plurality of overhangs and the shoulder cooperating to define a plurality of projection compartments therebetween. A valve cover is coupled to the housing and is positioned to engage the shoulder and a valve cover retainer is positioned within the outer bore. The valve cover retainer includes a plurality of projections selectively disposed within the plurality of compartments to lock the valve cover into engagement with the shoulder.

In still another construction, a fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore and a shoulder that divides the interior bore into a plunger bore and an outer bore, a plunger positioned within the plunger bore and operable to reciprocate along an axis within the plunger bore, and a plurality of overhangs formed as part of the housing. The plurality of overhangs extend into the outer bore and are spaced apart from one another to define a plurality of void spaces with each void space being between each adjacent two of the plurality of overhangs. The plurality of overhangs and the shoulder cooperate to define a plurality of projection compartments therebetween. A valve cover is coupled to the housing and positioned to engage the shoulder. A valve cover retainer includes a plurality of projections aligned with the plurality of void spaces such that the valve cover retainer is movable axially along the axis to an installed unlocked position within the outer bore, and wherein the valve cover is rotatable about the axis from the installed unlocked position to an installed locked positon within the outer bore, wherein in the installed locked position the plurality of projections are disposed within the plurality of compartments to lock the valve cover into engagement with the shoulder. A cap includes a plurality of interference projections selectively positioned within the plurality of voids to inhibit rotation of the valve cover retainer from the installed locked position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a representational device in a representational fluid end housing exemplifying features of the present invention; the features of the housing such as the plunger bore, discharge bore, suction bore and cross bore intersection are omitted for simplicity; the device is in the unlocked position;

FIG. 2a is a sectional view of the portion of the fluid end housing shown in FIG. 1 taken along view line 2-2 of FIG. 1 wherein the device is not sectioned but a representational cover in the housing is sectioned;

FIG. 2b is a sectional view of the portion of the fluid end housing shown in FIG. 1 taken along view line 2-2 of FIG. 1 wherein the device is not sectioned but a representational cover in the housing is sectioned, and the cover is configured to seat on a portion of the housing and is seated on a portion of the housing making the cover in FIGS. 2a and 2b different from each other;

FIG. 3 is the top view of the device in the portion of the fluid end housing shown in FIG. 1; the device is in the locked position;

FIG. 4a is a sectional view of the fluid end housing shown in FIG. 3 taken along view line 4-4 of FIG. 3 wherein the device is not sectioned but the cover in the housing portion is sectioned;

FIG. 4b is the sectional view of the fluid end housing shown in FIG. 3 taken along view line 4-4 of FIG. 3 wherein the device is not sectioned but a valve cover in the housing portion is sectioned, and the cover is the same as the cover in FIG. 2b accept the cover is seated on a portion of the housing making the cover in FIGS. 4a and 4b different from each other;

FIG. 5a is the sectional view of the fluid end housing shown in FIG. 1, exclusive of the device;

FIG. 5b is an isometric view of the section shown in FIG. 5 a;

FIG. 6 is a representational close up of the sectional view shown in FIG. 5a

FIG. 7a is a side view of the device shown in FIG. 1;

FIG. 7b is a top view of the device shown in FIG. 7 a;

FIG. 7c is a bottom view of the device shown in FIG. 7 a;

FIG. 7d is an isometric top view of the device shown in FIG. 7 a;

FIG. 8 is a top isometric view of the representational device and fluid end housing shown in FIG. 1 and further including a representational interference exploded therefrom;

FIG. 9a is a top and side isometric view of the interference shown in FIG. 8;

FIG. 9b is a bottom view of the interference shown in FIG. 9 a;

FIG. 10 is a sectional view of a representational fluid end housing having a suction bore, discharge bore, further bore and valve access bore useable in connection with the retainer and valve cover of FIG. 2; it is exclusive of the details of the compartment shown in the above figures;

FIG. 11 is a sectional view and partially exploded view of a representational device, valve assembly, and fluid end housing.

FIG. 12 is a sectional view of a representational stuffing box exploded from a sectional view of a representational fluid end housing;

DETAILED DESCRIPTION

While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, and is not intended to limit the invention to the specific embodiment illustrated.

FIGS. 1-6 show a device 20 having second portion 65 which is a coupling portion. The coupling portion comprises projections 28. Although the device is described herein with reference to a variety of retainers, a stuffing box, a discharge pipe and suction pipe, the term device as used herein is any device having a portion disposable in a compartment wherein the disposable portion comprises a coupling portion. The device could simply be a coupling comprising structure embodying the inventive features of projections 28. The device 20 shown in FIGS. 1-8 is a retainer and more particularly a valve cover retainer. The device 20 is disposed in a complimentary compartment 32 and the device is rotated from an unlocked to a locked position and vice versa.

In connection with the device 20 and compartment 32, FIGS. 1-6 also show a cover 22 and a housing 25 which form part of the fluid end assembly 24 of a positive displacement reciprocating pump. The housing 25 can be called a portion of a fluid end housing. The housing portion 25 can alternatively be called a housing 25 which is a generic housing to illustrate the features of the invention. The housing 25 shown in some of the figures omits some features of the housing such as the plunger bore, discharge bore, suction bore and cross bore intersection are omitted for simplicity. The device 20 comprises a shape which forms a generally equilateral triangle with junctions 28 a. The junctions are rounded and elongated in the circumferential 1 direction around central retainer axis 38. The shape in the radial direction has a generally equilateral triangular perimeter with rounded junctions. If the perimeter sides, exclusive of the rounded junctions, were continued until they intersect, the perimeter would form an equilateral triangle. The generally triangular shape of the device comprises three projections 28 which extend radially outward relative to and from a radially inward portion 36 of the device. The radial inward portion is a central body. Each projection 28 ends at a rounded junction 28 a. The rounded junctions are at an apex of each projection.

The device 20 is disposed in compartment 32 of the housing 25. The compartment 32 can be a device compartment and more particularly a retainer compartment. Although the compartment is described herein with reference to a variety of compartment types, it could be any compartment. The compartment 32, described herein, because it includes projection compartments 32 b and lock compartments 32 d, is an inclusive compartment.

The compartment 32 comprises a receiver 32 a which itself comprises a plurality of projection compartments 32 b. The compartment 32 comprises a lock 32 c which itself comprises a plurality of lock compartments 32 d. In an unlocked orientation, see FIGS. 1 and 2, each of the projections 28 are in a different one of the projection compartments 32 b. In the locked orientation, see FIGS. 3 and 4, each projection 28 is in one of the lock compartments 32 d. The device 20 is selectively moveable from the unlocked orientation to the locked orientation and vice versa. The change in orientation from the unlocked to the locked orientation and vice versa is achieved by relative circumferential movement, rotational relative movement, between the device 20 and the compartment 32 and/or projections compartments 32 b and/or lock compartments 32 d in a range of between only 10 and 270 degrees and preferably 60 degrees. In any event the rotation is less than 480 degrees. To provide the rotational relative movement from the unlocked to the locked orientation, the device 20 is first rotated by hand and then further rotated with a tool. To further secure the device in the locked orientation a removable interference 34 is used. The device 20, compartment 32, and interference 34 have constructions which allow for easy installation of the device 20 to the fluid end housing 25 and removal of the device 20 from the fluid end housing 25.

Now in more detail, the device 20 can comprise three sides 20 a. Each side 20 a converges towards at least two other sides 20 a. A perpendicular bisector of each side 20 a intersects with a junction 28 a joining the other two sides 20 a. Accordingly each side 20 a has a midpoint. A straight line can be drawn at a right angle to any side 20 a from the midpoint of the side to which the right angle is drawn and the line will intersect the junction 28 a joining of the two other sides 20 a.

The device has a radial outward portion, second portion 65. The radially outward portion of the device, the second portion 65, extends away from and outward of the radially inward portion 36 of the device, the device first portion 36. The inward first portion 36 at its second end 36 b can have a circular perimeter within the triangular perimeter and tangent to each of the three sides forming the triangular perimeter. Inward portion 36 at a first end 36 a has a circular perimeter. The radially outward portion, second portion 65, comprises a plurality of sections or portions. Each of the sections or portions, relative to the first portion 36, is a projection which extends radially outward relative to said first portion 36 and the central device axis 38. The device projections 28 extend in the radial direction at the second end 36 b of the first portion 36 away from the perimeter at the second end. The projections 28 also extend radially away from a perimeter of an intermediate portion 36 c of the first portion 36. The intermediate portion is between the first 36 a and second 36 b ends. The projections 28 comprise a plurality of adjacent pairs of projections arranged around central axis 38 of the retainer.

As shown in FIGS. 1-4, the device 20 is disposed in a void space 33 delimited by the housing 25. The void space is open to a bore 40 which can also be called a conduit 40 and is separated from that bore by a shoulder 41. The conduit/ bore is a valve access bore. The compartment 32 comprises the void space 33. The compartment 32 also comprises surfaces delimiting the void space 33. The void space 33 can also be considered part of the bore 40. The compartment void space 33 opens through an external surface 42 of said housing 25. The surface is recessed. The compartment 32 is joined to, integral with and part of the housing 25. The compartment 32 comprises the receiver 32 a and the lock 32 c. The receiver and lock are each joined to, integral with, and part of the housing. They are joined to and integral with each other. The lock 32 c can be called a coupler.

As noted, the receiver 32 a comprises the plurality of projection compartments 32 b. Each projection compartment 32 b comprises a void space 32 b′. The projection compartment void spaces 32 b′ form part of the compartment 32 void space 33. Each projection compartment comprises surfaces 58 a, 70 a, and 76 which delimit the compartment's void space.

Also as noted the lock 32 c comprises the plurality of lock compartments 32 d. Each lock compartment 32 d comprises a void space 32 d′. Each lock compartment void space 32 d′ forms part of the compartment void space 33. Each lock compartment comprises surfaces 58 b, 70 b, 78 delimiting the compartment's void space 32 d′. There is a plurality of adjacent pairs of lock compartments 32 d around axis 52. There is a plurality of adjacent pairs of projection compartments 32 b around axis 52. A different lock compartment 32 d and its void space 32 d′ is between, in the circumferential direction, each pair of adjacent projection compartments 32 b and their void space 32 b′ and a different projection compartment 32 b and its void space is between, in the circumferential direction, each pair of adjacent lock compartments 32 d and their void space. Each projection compartment void space 32 b′ between an adjacent pair of lock compartment 32 d void spaces 32 d′ is open to at least one of the lock compartment void spaces 32 d′ of the adjacent pair. The at least one lock compartment void space 32 d′ is on the side of the projection compartment void space 32 b′ in the first circumferential or angular direction 50. The first circumferential direction is clockwise In the present example each of the pair of adjacent lock compartment void spaces 32 d′ are open to the projection compartment void space 32 b′ between the adjacent pair. The lock compartments 32 d and their void spaces 32 d′and the projection compartments 32 b and their void spaces 32 b′ are in an alternating pattern, in the circumferential direction, around central axis 52 of retainer compartment 32.

In FIGS. 1 and 2 the device 20 is in the unlocked orientation. In FIGS. 3 and 4 the device 20 is in a locked orientation. In the unlocked orientation the device 20 is in the receiver 32 a. Each projection 28 is in a different one of the projection compartments 32 b and its void space 32 b′. The device first portion 36 is in a portion 39 of the compartment 32 radially inward of the projection compartments 32 b and their void spaces 32 b′. The first portion 36 is over and overlaps the cover 22 which in FIGS. 1-5 is a valve cover. In the unlocked orientation, the device 20 and its projections 28 are completely removable from the compartment 32. They are removable along a first direction 46 away from and out the compartment 32, the projection compartments 32 b, and the radially inward portion 39 of the compartment 32 without rotation of the device 20 relative to the housing 25 or lock 32 c or lock compartments 32 d. The first direction 46 is a direction along axis 38. In the unlocked orientation the device 20 is moveable in the first circumferential direction 50 around axis 38 and 52. It is rotatable around axis 38 and 52 in the first circumferential direction 50.

In the locked orientation, the device 20 is in the lock 32 c. Each projection 28 is in one of the lock compartments 32 d and its void space 32 d′ and in a different one of the lock compartments 32 d and its void space 32 d′. Each projection 28 is between surfaces 58 b, and 78 that delimit the lock compartment void space. The first portion 36 of the device 20 is in the radial inward portion 39 of the compartment 32 when the device 20 is in the locked orientation. The first portion 36 is not in any lock compartment 32 d when the device 20 is in the locked orientation. In the locked orientation, the device 20 is restrained and prevented from being removed from the compartment 32 and lock compartments 32 d in the first direction 46. The restraint occurs until the device 20 is oriented into the unlocked orientation. In the locked orientation the retainer is moveable in a second circumferential direction 54 around axis 38 and 52. It is rotatable around the axes in the second circumferential direction 54.

The lock 32 c restrains the device 20 from moving in the first axial direction 46. In the locked orientation the device 20 is engaged with the cover 22 such that the cover 22 is prevented from falling out of the conduit 40. The device 20 keeps the cover 22 in sealing engagement with the portion of the housing 25 forming the conduit 40 so as to close and seal off a portion of the conduit 40 from the external environment. The portion sealed off is between the cover 22 and a cross bore intersection 48 in the fluid end housing 25.

The device 20 is placed in an unlocked orientation by aligning the device 20 and then disposing the device in the receiver 32 a. The device 20 is aligned by orienting the projections 28 of the device over and to overlap the projection compartments 38 b and their void spaces. The device 20 is then moved in a second direction 56 towards a seat 58 a of the compartment 32. The second direction 56 is along central axis 52. The second direction is opposite the first direction 46. The phrase a direction along an axis or axial direction or axially as used herein is broad enough to include a direction having a vector in the axis' direction. The phrase a direction along a radius or radial direction or radially is broad enough to include a direction having a vector in the radius' direction. The device 20 is moved in the second direction 56 until the movement is prohibited. The movement can be prohibited by seat 58 a of the retainer compartment 32 which delimits the retainer compartment void space 33 and projection compartment void space 32 b′ in the second axial direction 56. Alternatively the movement can be prohibited by a member seated on seat 58 a such as cover 22. The device, to be oriented to the locked orientation from the unlocked orientation is moved around its axis 38 or axis 52 in the first circumferential direction 50, rotated, until the rotation is restrained and prevented. When the circumferential movement is completely restrained, it is in the locked position. To provide the rotational movement from the unlocked to the locked orientation, the device 20 is first rotated by hand and then further rotated with a tool. To go from the unlocked to the locked orientation requires rotation and circumferential movement of the device 20 around the axes 38 and 52 in a range which can be between 10 and 270 degrees in the first circumferential direction 50. In the present example it is rotated 60 degrees. In any event the rotation should be less than 480 degrees.

From the locked orientation, the device is easily orientated back to the unlocked orientation by moving the device in the circumferential direction around its axis in the second circumferential direction 54, rotating the device, until the projections 28 are aligned with the projection compartments 32 b. They are aligned when the projections 28 are free of the retainer lock compartments 32 b. The projections are free when removable from the projection compartment void spaces 32 b′ in the first axial direction 46 without further rotation of the device 20. To place the device in the unlocked orientation from the locked orientation the device is rotated, circumferentially moved around the axes 38 or 52. The rotation can be in a range of between 10 and 270 degrees in the second circumferential direction 54 achieve the alignment and place the device 20 in the unlocked position from the locked position. In the present example it is rotated 60 degrees. In any event it should be rotated less than 480 degrees. To provide the rotational movement from the locked to the unlocked orientation, the device 20 is first rotated with a tool.

The facilitate rotation of the device between the locked and unlocked orientation, the device has a coupling 100 The coupling 100 shown is a recess opening through the device first end 20 b and first portion first end 36 a . A sidewall delimiting the recess in the radial direction comprises a plurality of flat surfaces around retainer axis 38 in a hex pattern. Other coupling structures such as a hex bolt protrusion, spline, a series of holes, or anything that allows a fastener to be torqued can be used.

To further secure the retainer in the locked orientation the removable interference 34 is used. The interference 34 fits between adjacent pairs of junctions 28 a. A different interference projection 34 a of the interference 34 fits between each adjacent pair of junctions 28 a. Rotation of the interference 34 with the device 20 is prevented by a stop 60. The stop 60 comprises portions of the structure delimiting the housing 25 and compartment's void space 33.

Now referring to the device 20 in more detail, first end 36 a of the first portion 36 is at a first end 20 b and top of the device 20 and the second end 36 b of the first portion 36 is at a second end 20 c and bottom of the device 20. The second portion 65 of the device which comprises projections 28 has a first end 65 a and a second end 65 b. The second portion 65 has a height measured in the axial direction from its first end 65 a to its second end 65 b which is less than the height of the device measured in the axial direction from the first end 20 b of the device to the second end 20 c of the device. The axial height of the second portion 65 is also less than the axial height of the first portion 36 wherein the first portion is measured from the first end 36 a of the first portion to second end 36 b of the first portion. The height of the second portion 65 in the axial direction is the height of the projections 28 in the axial direction. Surfaces 28 b of the radially outward projections 28 of the second portion 65 are axially spaced from the device second end 20 c and first end 20 b. At least a portion of each surface 28 b is at the first end 65 a of the second portion.

The first portion 36 comprises a raised portion 36 d. It is raised in the axial direction relative to surfaces 28 b. The raised portion 36 d includes a plurality of curved sections 67 and a plurality of flat 68 sections all around axis 38. The curved sections 67 form a plurality of adjacent pairs of curved sections and the flat sections 68 form a plurality of pairs of flat sections. Each flat section 68 is between, in the circumferential direction, a pair of adjacent curved sections 67 and each curved section 67 is between, in the circumferential direction, a pair of adjacent flat 68 sections. The curved sections 67 and flat sections 68 are around axis 38 in an alternating pattern. The curved 67 and flat 68 sections are part of a continuous sidewall of the raised portion. The raised portion 36 d has a circumferential and circular rim proximate the retainer first end 20 b and first portion first end 36 a. The flat sections 68 are equally spaced along the outer circumferential rim of the raised portion so that their center will align with the midpoint of sides 20 a in the upward direction. Each of the flat sections 68 of the raised portion 36 d are at a respective different side 20 a and seamless with its respective side 20 a. The flat sections 68 are placed to aid installation of interference 34.

The surfaces 28 b of the projections 28 are external surfaces. Each of the surfaces 28 b has at least a portion that is inclined and helical. The helical incline, going in the second circumferential direction 54, extends up in the direction away from the device second end 20 c towards the device first end 20 c in the first axial direction 46. Accordingly each projection has a helically inclined portion as just described. The pitch of the helical form is .269 inches. The pitch is the increase in height in the first direction 46 if the helical form was carried for 360 degrees around the device axis in the second circumferential direction. The angle of incline extending up in the first axial direction, as measured along a radius of the projection, which corresponds to the pitch, is from 0.6 to 0.8 degrees. The angle is generally greatest at the base and smallest at the apex of the projection. The incline is measured relative to a plane normal to the device central axis. It is believed the minimum pitch could be 0.003 inches with the average helical angle of incline ranging from 0.007 degrees to 5 degrees depending on the radius of the device. The incline is relative to a surface of the projection at the projections second end 65 b. The surface is opposite the inclined surface 28 b. The projection along the incline increases in thickness in the second circumferential direction and along the axis of the retainer in the first direction. Each projection 28 also has a beveled leading edge which facilitates easy rotation by the user when they install the valve retainer into the housing.

In more detail, each projection compartment 32 b and lock compartment 32 d comprises a respective sidewall 70 a 70 b. The projection compartment sidewalls 70 a and lock compartment sidewalls 70 b are curved around axis 52. Each sidewall 70 a delimits a respective different void space 32 b′ of each projection compartment in the radial direction. Each sidewall 70 b delimits a respective different void space 32 d′ of each lock compartment in the radial direction. Each sidewall 70 a, 70 b is part of a continuous, circumferential seamless sidewall.

Each lock compartment comprises a structure 74 which projects radially inward relative to its respective compartment sidewall 70 b. The structures 74 are overhangs. There is a plurality of adjacent pairs of overhangs 74. Each overhang 74 has an inclined and helical portion 78. The helically inclined portion 78 comprises a seat facing surface. The helical portion 78 has an incline, going in the second circumferential direction, extending upwards in the first axial direction 46 away from a seat 58 b and towards the void space opening through the housing surface 42. The incline is helical. The helical incline is best seen in FIG. 6. The pitch of the helical form of the incline is 0.269 inches. The pitch is the increase in height in the first direction 46 if the helical form was carried for 360 degrees around the retainer compartment axis in the second circumferential direction. The angle of incline extending up in the first axial direction, as measured along a radius of the overhang, which corresponds to the pitch, is from 0.6 to 0.8 degrees. The angle is generally greatest at the base and smallest at the apex of the overhang 74. The incline is measured relative to a plane normal to the retainer compartment central axis. The incline is measured relative to a plane normal to the retainer compartment central axis. It is believed the minimum pitch could be 0.003 inches with the average angle of incline ranging from 0.007 degrees to 5 degrees depending on the radius of the device. The incline is relative to a surface of the overhang opposite the inclined surface 78. The overhang along the inclined portion increases in thickness in the second circumferential direction and along the axis of the compartment in the first direction. The helical portion 78 of an overhang 74 and helical portion 28 b of the projection creates a downward force on the projections of the device when the device is rotated from the unlocked to the locked position. The downward force helps hold the device 20 in place and puts it in engagement with the cover 22.

Each projection compartment 32 b comprises a circumferentially delimiting side surface from each of a pair of adjacent overhangs 74. Each circumferentially delimiting side surface of its respective projection compartment 32 b, delimits the void space of that projection in the circumferential direction. Each projection compartment comprises an axially elongated sidewall 76 which delimits each compartment's void space in the radial direction. Each axially elongated sidewall 76 projects in the axial direction away from its compartment's sidewall 70 a and towards the housing surface 42 through which the retainer compartment void space 33 opens. The elongated sidewalls 76 are about the same radial distance from axis 52 as are sidewalls 70 a. Thus each projection compartment sidewall 70 a and elongated sidewall 76 forms a single sidewall which is seamless. There is a plurality of adjacent pairs of elongated sidewalls 76. Each elongated sidewall 76 is between, in the circumferential direction, a pair of adjacent overhangs 74. Each overhang 74 is between, in the circumferential direction, a pair of adjacent elongated sidewalls 76. The sidewalls 76 and overhangs 74 are arranged in alternating pattern around axis 52.

Each projection compartment 32 b includes a seat 58 a and each lock compartment 32 d also includes a seat 58 b. Each seat 58 a, 58 b extends away from its respective compartment's sidewall in the radial direction. Each projection compartment seat 58 a delimits the projection compartment void space 32 b′ in the axial direction. Each lock compartment seat 58 b is axially spaced from its overhang 74 and delimits the compartment's void space 32 d′ in the axial direction. Each seat 58 a, 58 b of its respective compartment can support a cover as shown in FIGS. 2b, 4b , 11 or supports a projection as shown in FIGS. 2a and 4a or support the first inward portion 36 as shown in FIG. 12. The seats 58 a, 58 b form a continuous and seamless seat. The cover 22 can be oriented in the conduit 40 such that its upper surface is aligned with the seat 58 a, 58 b of each compartment. The cover 22 could be constructed to have an engaging surface facing the seat 58 a, 58 b and engaged with the seats 58 a, 58 b. See FIGS. 2b and 4b . The cover upper surface would be above and overlap the seat 58 a, 58 b. The second end 20 c of the device is in engagement with the valve cover upper surface when the device 20 is in the locked or locked orientation.

The retainer compartment 32 comprises the continuous side wall 70 a, 70 b, continuous seat 58 a, 58 b, overhangs 74, and elongated sidewalls 76. Although the seat 58 a, 58 b are shown to engage the device 20 at the device's second end 20 c.

After the device 20 is installed in the housing 25, the interference 34, which can be called an anti-rotation cap, is installed. The structural details of the anti-rotation cap are shown in FIGS. 8, 9 a-9 b. Anti-rotation cap projections 34 a make an angle with an axis of the interference and extend from a first end 34 b the interference towards a second end 34 c in the axial direction. A carrier 34 d, which can be a plate, carries the projections 34 a. The carrier 34 d is at the first end 34 b. Each projection 34 a, towards the second end 34 c has a nub 34 e. The nub is a curved portion of the projection 34 a. The interference 34 includes the same number of projections 34 a as there are device projections 28. Carrier 34 d has a continuous edge that includes straight segments 34 d′ and curved segments 34 d″. The projections 34 a are arranged around the central axis of the interference 34. One projection 34 a is at each curved segment 34 d″. The carrier 34 d has a first layer 34 g integral and seamless with the projections 34 a. The carrier has a second layer 34 f coupled to the first layer 34 g. The second layer 34 f provides a grasping structure to hold the carrier 34. When the anti-rotation cap is installed each interference projection 34 a is between, in the circumferential direction, a different pair of junctions 28 a of retainer projections 28 and along a different side 20 a. When installed each projection 34 a is at a different projection compartment 32 b. Also when installed the nub 34 e of each projection is in a void space of a cutout region. Each cutout region 32 b″ is at a projection compartment. The cutout is formed in the housing 25. The nubs 34 e are snapped into the cutout region 32 b″ void spaces by moving the interference in the second axial direction 56. The anti-rotation cap prevents the device 20 from rotating during the pumps operation. This reduces the fatigue on the device and it allows it to be used for longer periods of time than those disclosed in the prior art.

In FIG. 10 the housing 25 is shown with a discharge bore 25 a, a suction bore 25 b, a further bore 25 c, and cross bore intersection 48. The further bore 25 c is associated with a pumping member such as a piston or plunger. The discharge bore 25 a, the suction bore 25 b, and the further bore 25 c each open into the cross-bore intersection 48. A suction valve assembly, not shown, is in the suction bore and a discharge valve assembly, not shown in FIG. 10, is in the discharge bore. In a well-known manner, during the upstroke of the pumping member, not shown, fluid is taken into the housing 25 over the suction valve and into the suction bore 25 b and cross-bore intersection 48. During the pumping member's downs stroke, the fluid taken in is discharged through the discharge bore 25 a and over the discharge valve assembly and out the fluid end housing 25.

The fluid end housing 25 also has the bore or conduit 40 which in FIG. 1-10 is a valve access bore. The conduit/bore 40 allows for the removal and installation of the suction valve assembly from the housing 25. During operation, the conduit 40 is sealed off with cover 22. The cover is held in place by device 20. The device is engaged to the housing in the locked orientation as described above. The fluid end housing 25 in FIG. 10 for simplicity omits the details of the compartment 32. The compartment would however be configured in the fluid end at around area 101. The compartment 32 can be considered a portion of the fluid end housing 25 or a separate component attached the housing 25. In either case it is carried by a portion of the fluid end housing 25.

The device 20 can also be configured as a retainer 320 for discharge valve cover 110 that has been configured to embody a discharge gage connector. Of course it could be configured to retain other types of valve covers. Features of device 320 correspond to features found in device 20. Device 320 has a different shape than the device 20 shown in FIGS. 1-7. For instance device 320 does not have sides which correspond to sides 20 a. The corresponding features when called out in FIG. 11 are indicated with the same reference number as those used for device 20 except a “3” proceeds the number. Thus projection 28 for device 20 corresponds to projection 328 for device 320. Notably device 320 has a central hole 114 to receive a portion of the discharge valve cover 110 which embodies the discharge gage connector. The central hole 114 is within first portion 336 and delimited by a portion of first portion 336.

As shown in FIG. 11 the valve cover 110 serves as a cover and a spring retainer for the discharge valve assembly 112. The discharge valve assembly 112 is in discharge bore 25 a which as shown in FIG. 11 is specially configured for the valve assembly 112 and specially configured with a type of compartment 332 to receive device 320. The compartment 332 receives the device 320 as indicated by FIG. 11. In FIG. 11 compartment 332 opens through an external surface 342 of the housing 25 and opens into a portion of the discharge bore 25 a. The fluid end housing 25 shown in FIG. 11 would also have a suction bore, a valve access bore, a further bore, and a cross bore intersection. The compartment 332 in FIG. 11 is a retainer compartment and it is configured like compartment 32 and is a type of the compartment 32 set forth in FIGS. 1-6. Features of compartment 32 correspond to features found in compartment 332. The corresponding features when called out in FIG. 11 are indicated with same reference number as those used for compartment 32 except a “3” precedes the number. Thus overhang 74 for compartment 32 corresponds to overhang 374 for compartment 332.

The fluid end housing 25 shown in FIG. 10 has a non-descript stuffing box 102 which has an open area or bore 102 a which opens into and is adjacent to a portion of the plunger bore 25 c. The stuffing box has an open end 102 b opposite the open area. The open end opens through an external surface 242. The open end 102 b is bounded by a flange. The stuffing box 102 holds a plurality of seals, packing (not shown). The packing would be disposed around a reciprocating member such a plunger. The plunger would reciprocate in the stuffing box 102 and in the packing. The seals (packing) would prevent the water from escaping from the fluid end housing around the plunger as it reciprocates in the plunger bore. In FIG. 10, the stuffing box 102 is integral and seamless with the portion of the fluid end housing to which it is coupled.

In some cases, such as in FIG. 12, the stuffing box 420 is coupled to a compartment 532 of the fluid end housing 25. In either case the stuffing box can be considered a portion of the fluid end housing 25 or a component attached to the fluid end housing 25. In either case it is carried by a portion of the fluid end housing 25. The stuffing box 102 can be considered an entry portion of the further bore 25 c or an entry way into the bore 25 c.

FIG. 12 shows stuffing box 420 designed to be removably coupled to compartment 532 of the fluid end housing 25. The stuffing box 420 itself has a compartment 232 to receive a device like device 20. The device, which is a retainer, holds the packing in the stuffing box 420. The device is a type of device 20. The device for the stuffing box would primarily differ from device 20 shown in FIGS. 1-7 in that it would have a central hole represented by dashed lines 220 in FIGS. 7b and 7c to receive the plunger. The compartment 232 of the stuffing box which receives the device has the same features as compartment 32. Again the corresponding features use the same reference numbers except the reference numbers for compartment 232 are preceded by a “2”. Thus overhang 74 of compartment 32 is shown as 274 for compartment 232. As shown, compartment 232 has projection compartments 232 b. Each compartments 232 b has void space 232 b′ and seat 258 a. The compartment also has lock compartments 232 d. Each compartment has void space 232 d′, overhang 274, inclined portion 278 and seat 258 b. The compartment opens through external surface 242. The compartment 232 opens into a portion of the stuffing box opening 102 a. The compartment 232 is shown as an integral feature of the stuffing box 420. It could be a separate component. In either case it would be carried by a portion of the stuffing box 420. It would also thus be carried by a portion of the fluid end housing 25.

The stuffing box 420 shown in FIG. 12 is itself another type of device 20. The device 420 shown in FIG. 11 is similar to device 20 shown FIGS. 1-6. Again the corresponding features use the same reference numbers except the reference numbers for device 420 are preceded by a “4”. Thus projection 28 of device 20 is shown as 428 for device 420. Notably device 420 has a central hole 102 a to receive the packing and plunger. The central hole 102 a is within first portion 436 and delimited by first a portion of first portion 436. The first portion is a stuffing box body. Device 420 includes an attachment portion in the form of coupling features embodied by projections 28. Accordingly the stuffing box 420 comprises a plurality of projections 428 spaced around a central long axis of the stuffing box. Each projection 428 is configured like projections 28. The projections 428 are arranged about stuffing box body like projections 28 are arranged about the radially inward first portion 36.

The stuffing box 420 is coupled to a portion of the fluid end 25 by way of an attachment portion in the form of a compartment 532 which is like compartment 32. The compartment 532 opens through an external surface 542 of the fluid end housing 25 and opens into a portion of further bore 25 c which corresponds generally to bore 25 c in FIG. 10. The further bore in this case is a plunger bore. Again the corresponding features use the same reference numbers except the reference numbers for compartment 532 are preceded by a “5”. Thus overhang 74 of compartment 32 is shown as 574 for compartment 532.

A discharge pipe or suction pipe are other types of devices 20. They could be configured to embody the coupling features embodied by projections 28. The pipes would comprise a plurality of projections spaced around a central long axis of the pipe. Each projection would be configured like projections 28. The projections would be arranged about the pipe body like projections 28 are arranged about the radially inward first portion 36.

The suction pipe or discharge pipe would be coupled to a portion of the fluid end 25 by way of a respective compartment configured like compartment 32.

Preferably the device 20 regardless of type such as stuffing box 420, or retainer 320 is seamless. At least the projections of the device are seamless with the central body of the device. Similarly the compartment 32 is preferably seamless. At least the overhang portions 74 of the lock compartments 32 d are seamless with the portion of the compartment 32 from which they project.

The projections 28, 328, and 428 of their respective devices have been described with a construction that increases in thickness to provide the inclined helical surface 28 b, 328 b and 428 b. The helical inclined surface 28 b, 328 b, and 428 b could be provided with a projection with a construction that does not increase in thickness. It could have a uniform and constant thickness. In this case the entire projection would be angled relative to a plane normal to the central axis of the device. The inclined projection could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. Thus the projection of constant thickness still has inclined surface 28 b, 328 b, and 428 b which could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. In this case the central body of the device would provide support for the device in the axial direction. It is believed this structure is not as satisfactory.

The overhangs 74, 274, 374 and 574 of their respective lock compartments have been described with a construction that increases in thickness to provide the inclined helical surface 78, 278, 378 and 578. The helical inclined surface 78, 278, 378 and 578 could be provided with an overhang with a construction that does not increase in thickness. It could have a uniform and constant thickness. In this case the entire overhang would be angled relative to a plane normal to the central axis of the compartment. The inclined overhang could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. Thus the overhang of constant thickness still has inclined surface 78, 278, 378 and 578 which could have a minimum pitch of 0.003 inches with an average helical angle ranging from 0.007 degrees to 5 degrees depending on the radius of the compartment. It is believed this structure is not as satisfactory. 

What is claimed is:
 1. A fluid end assembly of a high pressure reciprocating pump, said fluid end assembly comprising: a housing defining an interior bore, a first opening at a first end of the interior bore, and a shoulder that divides the interior bore into a plunger bore and an outer bore; a plurality of overhangs formed as part of the housing and extending into the outer bore; a plunger positioned within the space and operable to reciprocate along an axis within the plunger bore; a valve cover coupled to the housing and positioned to engage the shoulder to close the first opening; and a valve cover retainer positioned within the outer bore, the valve cover retainer including a plurality of projections arranged to selectively engage the plurality of overhangs to sandwich the valve cover retainer between the valve cover and the housing to lock the valve cover into engagement with the shoulder.
 2. The fluid end assembly of claim 1, wherein each of the plurality of overhangs includes a first inclined surface juxtaposed with the shoulder.
 3. The fluid end assembly of claim 2, wherein each of the plurality of projections includes a second inclined surface arranged to selectively engage the first inclined surface.
 4. The fluid end assembly of claim 2, wherein the first inclined surfaces and the second inclined surfaces are helical.
 5. The fluid end assembly of claim 1, wherein the plurality of overhangs cooperate to define a plurality of void spaces, each void space sized to allow the passage of one of the plurality of projections.
 6. The fluid end assembly of claim 5, wherein the valve cover retainer is inserted into the outer bore axially with each of the plurality of projections aligned with one of the plurality of void spaces.
 7. The fluid end assembly of claim 6, further comprising a cap including a plurality of interference projections, the interference projections selectively positioned within the plurality of voids to inhibit rotation of the valve cover retainer from the installed locked position.
 8. A fluid end assembly of a high pressure reciprocating pump, said fluid end assembly comprising: a housing defining an interior bore and including a first attachment portion formed as part of the housing; a packing box having a second attachment portion, an interior bore, and a shoulder that divides the packing box into a first portion and a second portion, the first attachment portion and the second attachment portion engageable with one another to attach the packing box directly to the housing; a plurality of overhangs formed as part of the packing box and extending into the second portion, the plurality of overhangs and the shoulder cooperating to define a plurality of projection compartments therebetween; a quantity of packing positioned within the first portion; and a retainer positioned within the second portion, the retainer including a plurality of projections selectively disposed within the plurality of compartments to lock the retainer into engagement with the shoulder.
 9. The fluid end assembly of claim 8, wherein each of the plurality of overhangs includes a first inclined surface juxtaposed with the shoulder.
 10. The fluid end assembly of claim 9, wherein each of the plurality of projections includes a second inclined surface arranged to selectively engage the first inclined surface.
 11. The fluid end assembly of claim 9, wherein the first inclined surfaces and the second inclined surfaces are helical.
 12. The fluid end assembly of claim 8, wherein the plurality of overhangs cooperate to define a plurality of void spaces, each void space sized to allow the passage of one of the plurality of projections.
 13. The fluid end assembly of claim 12, wherein the retainer is inserted into the second portion axially with each of the plurality of projections aligned with one of the plurality of void spaces.
 14. The fluid end assembly of claim 13, wherein the housing includes a second shoulder that divides the interior bore into a bore portion and an engagement portion, and wherein the first attachment portion includes a plurality of overhangs formed as part of the housing and extending into the engagement portion, the plurality of overhangs and the second shoulder cooperating to define a second plurality of projection compartments therebetween.
 15. A fluid end assembly of a high pressure reciprocating pump, said fluid end assembly comprising: a housing defining an interior bore and a shoulder that divides the interior bore into a plunger bore and an outer bore; a plunger positioned within the plunger bore and operable to reciprocate along an axis within the plunger bore; a plurality of overhangs formed as part of the housing, the plurality of overhangs extending into the outer bore and spaced apart from one another to define a plurality of void spaces with each void space being between each adjacent two of the plurality of overhangs, the plurality of overhangs and the shoulder cooperating to define a plurality of projection compartments therebetween; a valve cover coupled to the housing and positioned to engage the shoulder; a valve cover retainer including a plurality of projections, the plurality of projections aligned with the plurality of void spaces such that the valve cover retainer is movable axially along the axis to an installed unlocked position within outer bore, and wherein the valve cover is rotatable about the axis from the installed unlocked position to an installed locked positon within the outer bore, wherein in the installed locked position the plurality of projections are disposed within the plurality of compartments to lock the valve cover into engagement with the shoulder; and a cap including a plurality of interference projections, the interference projections selectively positioned within the plurality of voids to inhibit rotation of the valve cover retainer from the installed locked position.
 16. The fluid end assembly of claim 15, wherein each of the plurality of overhangs includes a first inclined surface juxtaposed with the shoulder.
 17. The fluid end assembly of claim 16, wherein each of the plurality of projections includes a second inclined surface arranged to selectively engage the first inclined surface.
 18. The fluid end assembly of claim 16, wherein the first inclined surfaces and the second inclined surfaces are helical.
 19. The fluid end assembly of claim 18, wherein the first inclined surface and the second inclined surface are engaged such that rotation of the valve cover retainer about the axis displaces the valve cover retainer axially along the axis.
 20. The fluid end assembly of claim 15, wherein the cap includes a nub arranged to engage the housing to retain the cap in engagement with the housing. 